>Finally, writing inserts and updates as JSON is convoluted. What should be a fairly simple operation like: "atomic increment this nested value, or insert if value is not there" was simply a disaster. For example, increment "api" by one, or insert "api":1 if necessary [...]

Maybe I'm missing something, but wouldn't `db.coll.update_one(search_query, {"$inc": {"visit_count.api": 1}})` do the trick?

Overall, I've been very happy with MongoDB (and their Atlas serverless offering). I would still default to recommending Postgres "by default", but for those use cases where MongoDB makes sense, it shines.